1. Field of the Invention
The present invention relates to a fixing device for assembling objects, then quickly releasing them, and which comprises to this end, on the one hand, an attaching element that can be made integral with one of the objects to be held together and, on the other hand, retaining means that can be made integral with the other object and configured so as to hold, before the release, said holding element, said retaining means being formed of bringing closely together, around a securable part of said holding element, several separable parts held close together by disengageable pre-tensioning means.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Fixing devices of this type are already known, which find an application essentially in the field of space navigation, where they are used for stacking appendices onto satellites, for example the solar-energy generators. In launching position, the folded appendices are fixed by means of fixing devices. After launching, these fixing devices are activated, which results into releasing the attaching means and into permitting the unfolding of the appendices of the satellite.
The disengaging of the pre-tensioning means generally occurs pyrotechnically, which has the drawback of causing impacts in the structure of the satellites or of their appendix, these impacts being due either to the pyrotechnical operation or to the sudden release of the potential energy accumulated by the tension on the parts of the retaining means.
In order to cope with these drawbacks, there has been proposed that the disengageable pre-tensioning means consist of a wire wound around the separable parts, wherein wire is fully or partially fusible, so as to permit the separation of said separable parts.
Thus, FR 2 756 619 shows a releasing device, which comprises, on the one hand, a retaining nut integral with one of the objects to be held together and formed of two parts, one pivotally mounted onto the other one that is fixed, so as to be able to separate from the latter under the action of a spring and thus open and, on the other hand, a rod the end of which is threaded, integral with another one of the objects to be held together, said parts, which have an inner thread, are maintained tightened onto said threaded end, in order to maintain it under pre-tension by means of a wire wound around them, the ends of said wire being maintained by fusible wires under the action of an electric voltage.
Such a device has the drawback that only the pivoting part can separate during the release and that, therefore, the disengagement of the threaded end requires not only the pre-tensioning, but also a displacement in the transversal direction of said threaded end with respect to the fixed part of the retaining nut, which, depending on the field of application, can be detrimental to the displacement of the objects after the release. Furthermore, when there exists a tension between the two objects, the release can produce an unwanted, or uncontrolled, displacement, of the objects with respect to each other.
EP 1 255 675 describes a fusible actuator with redundant current-supply, which comprises retaining means formed of a plurality of parts maintained tightened around the head of a securing pin by a retaining wire wound around said parts and an end of which is fusible under the action of an electric voltage. It should be noted that such a device has the drawback of a possible escape of the parts with the risk of damaging the objects to be held together.